The Dielectric Properties of Native Starch Solutions—a Research Note

The dielectric properties of four native starch solutions, both gelatinized and ungelatinized with concentrations from 5 to 30% over the temperature range from 3°C to 95°C, were measured by a cavity perturbation technique at 175 GHz. The dielectric properties of the starch types did not differ from each other; the most important factor affecting the dielectric properties was the water content. Both the real permittivity (ε’) and the loss factor (ε”) decreased with increasing temperature and increasing starch concentration. The differences between gelatinized and non gelatinized samples were small, the ε’” of non gelatinized starch being 2–3% higher and the ε up to 5% lower than gelatinized starch.